Research Article |
Corresponding author: Carmen Acedo ( c.acedo@unileon.es ) Academic editor: Maria Vorontsova
© 2019 Carmen Acedo, Félix Llamas.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Acedo C, Llamas F (2019) A new species of perennial Bromus (Bromeae, Poaceae) from the Iberian Peninsula. PhytoKeys 121: 1-12. https://doi.org/10.3897/phytokeys.121.32588
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During a survey of the genus Bromus for the ongoing Flora Iberica, B. picoeuropeanus sp. nov., a new orophilous species of perennial Bromus from Picos de Europa National Park, was found, and it is described and illustrated here. This new species belongs to the Bromus erectus complex and differs from the other perennial species of this group occurring in the Iberian Peninsula in its well-developed rhizome, the small innovation leaves and all peduncles and branches shorter than the spikelets. B. picoeuropeanus grows on calcareous stony soils associated with dry places. We provide a description and illustrations of the new species and an identification key for the most related European perennial species belonging to the complex.
Bromea, Bromus subg. Festucoides, Bromus erectus complex, Bromus picoeuropeanus, Cantabrian range, Identification Key, New species, Poaceae, Spain, Taxonomy
The genus Bromus L. is the only representative of the tribe Bromeae in Southwest Europe. The genus comprises perennial and annual species, and both life forms are distributed throughout the genus. Bromus has a characteristic fleshy appendage above the style insertion, which is pubescent at its apex and persistent in the caryopsis. The taxonomy of this genus is considered troublesome and has been the subject of numerous regional taxonomic revisions (e.g.
The last revision of the genus Bromus L. in the Iberian Peninsula (
The European perennials belong to Bromus subg. Festucoides (Coss. & Durieu) Hackel, which is not monophyletic in its current circumscription (
The main objectives of this study are to describe a new species, to differentiate it from its relatives, and to characterize this new taxon.
Several specimens of perennial Bromus were collected during a survey of the genus Bromus for the ongoing Flora Iberica project. This material was confirmed as a new species after a careful study and comparison with material deposited at JBAG, LEB, FCO, MA, MAF, JACA, SALA, SANT, VIT, representing the full distribution and variability of B. erectus Huds. from the Iberian Peninsula as well as specimens belonging to related species (B. condensatus Steud., B. stenophyllus Link, B. transsilvanicus Steud.) and other perennial European species (B. biebersteinii Roem. & Schult., B. moellendorffianus (Asch. & Graebn.) Hayek, B. moesiacus Velen., B. pannonicus Kumm. & Sendtn., B. riparius Rhemann, B. tomentellus Boiss.). In addition, material from several important European Herbaria: C, K, FI, MSNM was studied. We also studied specimens and photographs of types and original material in B, P, and K, including the type specimen of B. erectus (
Specimen locality data were recorded in the field or via geo-referencing. We assessed the preliminary conservation status of the new species using our field knowledge, applying the
Summary of the main taxonomic traits that differentiate Bromus picoeuropeanus Acedo & Llamas from B. erectus Huds.
B. picoeuropeanus Acedo & Llamas | B. erectus Huds. | |
---|---|---|
Habit | Loosely tufted | Densely caespitose |
Rhizome presence | Rhizomatous | None, or inconspicuous rhizome, caespitose |
Height | Up to 40 cm | 60–130 cm |
Basal and cauline leaf blade | Flat, basal similar to the cauline, 2–3.5 mm wide | The basal narrower (c.1 mm) and longer than cauline (2–3 mm wide) |
Ligule | Truncated or rounded, 0.5- 1 mm | Blunt, (0.5)1–2 mm |
Panicle in well-developed specimens | Contracted, 3–5(–8) cm length | Spreading, 10–20 cm length |
Spikelet number | 4–8(–11) | (8)20-30 |
Spikelet length | 16–21 (–25) mm | (15–)20–35(50) mm |
Branch length | Shorter than spikelet | Several branches equal to or longer than spikelet |
Lower glume length | 6–7 mm | 7–12 mm |
Upper glume length | 7–9 mm | (8–)9–14(–15) mm |
Fertile lemma length | 9–11(–12) mm | (9–)10–15 (–18) mm |
Palea length | Similar to lemma | Similar to lemma |
Awn length | (2.5–)4.5–5 mm | 2.5–6(8) mm |
Florets number | (4–)5–7 | (5–)7–9 |
Anther length | 3.5–4.5 mm | 4.5–8 mm |
Caryopsis | Thickened, inrolled shorter than palea 8–9 mm | Thin and almost flat, similar to palea in length |
Spain. Cantabria: Macizo Oriental de Picos de Europa, Vegas de Ándara: Fuente de la Escalera. 43°12.42'N, 4°42.20'W, [WGS-84], on limestone dry rocky sites, moving by gelifraction, 1869 m alt., 31 August 2011; C. Acedo, A. Alonso & F. Llamas CA247.4 (Holotype LEB 121814).
Bromus picoeuropeanus differs from B. erectus Huds. (Table
Perennial plant with long rhizomes 3–5(7) cm, loosely tufted. Flowering culms up to 40 cm. Culms channeled and glabrous, with glabrous nodes. Extravaginal innovation leaves with short blades, similar to the cauline leaves. Leaf sheaths of cauline leaves glabrous. Old basal leaf sheaths persistent, investing the culm base. Blade of cauline leaves 9–13 cm × 2–3 mm, tapering gradually towards the apex. Ligule membranous and glabrous, short, 0.5–1 mm, apex truncated or rounded, ± lacerated. Panicle 3–4(–8) × 2–3 cm, erect, lax, contracted, with 4–8(11) spikelets, branches slender. Scale of the lower node leaf-like, c. 4 mm, glabrous. Pedicels scabrid with fine antrorse teeth. All branches and pedicels shorter than spikelets. Spikelets 16–22(–25) × 3–5 mm, with two unequal glumes and 4–5(–7) fertile florets, imbricate when young, in maturity the florets slighted separated. Lower florets bisexual, 9–11(–12) mm, oblong, scaberulous toward the apex; upper floret male or sterile, 5–6 mm, lanceolate, glabrous, similar in color and texture to the lower florets. Lower glume 1–veined, narrow, 6–7 mm. Upper glume 3-veined, 7–9 mm. Lemma glabrous, lanceolate, section slightly keeled, 9–11(–12) mm (excluding the awns), 3–5-veined. Apex of the lemma slightly emarginate (sinus approximately 0.1 mm); margin rounded. Awn short, (2.5–) 3–4 (–5) mm, up to 1/3 the lemma length, fine and straight, inserted 1–1.5 mm below the apex. Rhachilla 2–3 mm, scabrid with very fine antrorse teeth. Callus short, glabrous and rounded. Palea linear-lanceolate of similar size or slightly shorter than the lemma, 8–11 × 1–2 mm, with aculeolate keels; wings nearly as wide as the palea body, with smooth border. Lodicules 2, lanceolate to oblong, glabrous, 0.5–1.5 mm long. Stamens 3, with anthers 3.5–4.5 mm long. Caryopsis elliptic, enrolled or plicate at maturity, 7–8 mm, shorter than palea (Fig.
Bromus picoeuropeanus. A Habit showing the developed rhizomes, the short basal leaves, and the contracted inflorescence B Spikelet with unequal glabrous glumes and five florets C Glumes D Palea in adaxial view, showing the two adaxial wings E Lemma in lateral view (drawn from the holotype) F Caryopsis in adaxial and abaxial view (drawn from LEB 121815). Drawings by Ms. Giulia Osti, 2018.
Flowering July – August. Fruiting August – September.
Bromus picoeuropeanus is endemic to the Iberian Peninsula and occurs in Spain, distributed through the Northern Mountains of the Cantabrian Range (Fig.
Bromus picoeuropeanus occurs within the Picos de Europa National Park. Although the
Some thirty perennial species belonging to the genus Bromus occur in the Euro+Med area (
The Bromus erectus complex is differentiated by its persistent basal sheaths remaining intact or decaying into parallel fibers, and the non-cauline basal leaves typically longer and narrower than the cauline leaves. Its inflorescence is lax, spread or contracted, with erect branches and pedicels, more or less developed, but some of the pedicels longer than the spikelet. The multiflorous spikelet is supported by two subequal or unequal glumes with 1–5 nerves (
The morphological traits of Bromus picoeuropeanus suggest it must be classified within the Bromus erectus complex. Among the Iberian perennials, the specimens of B. picoeuropeanus are morphologically more similar to the widespread B. erectus. The presence of a developed rhizome 3–5(7) cm long (Fig.
A The preferred habitat of Bromus picoeuropeanus in stony and unstable soils, c. 1900 m elevation, where it prefers steep slopes and stony grassland, and disappears when the slope decreases or the pasture becomes denser B Detail of the basal part of culms showing the long rhizomes and flat cauline leaves.
While Bromus erectus has a wide distribution in most of Europe (except on the Scandinavian peninsula and the adjacent Northeastern countries), B. picoeuropeanus is known only in the National Park of the Picos de Europa, a small territory of the Cantabrian range. B. picoeuropeanus differs also in its ecological behavior from all the native Iberian perennial species. B. benekenii and B. ramosus occur in nemoral habitats and B. erectus mainly in mesophyllous meadows. B. picoeuropeanus, by contrast, occurs in stony and rocky places.
1 | Plants rhizomatous, laxly caespitose; shoot and cauline leaf-blades similar in width, leaves glabrous, scabrid or distinctly pilose | 2 |
– | Plants without rhizomes or stolons, or inconspicuously rhizomatous, tufted, caespitose; cauline leaf blades wider than the lower, with scattered long (up to 1mm) and patent hairs | 6 |
2 | Leaves flat or slightly involute | 3 |
– | Leaves conduplicate, or setaceous-conduplicate | 4 |
3 | Rhizome long; lemma 9–11(–12) mm, awn 3–5mm; caryopsis slightly thickened, inrolled at maturity, shorter than palea; leaves not auriculate; culms up to 40 cm | B. picoeuropeanus |
– | Rhizome short, forming distinct clumps; lemma long 11–14(–20) mm, awn 5–8 mm; caryopsis almost flat, similar in length to the palea; lower leaves shortly auriculate; culms 50–90(–120) cm | B. riparius |
4 | Leaves and sheaths with long greyish hairs; spikelets 15–20(–25) mm | B. pannonicus |
– | Indumentum of leaves different; spikelets 15–25(–35) mm, awn similar in length to the lemma or slightly shorter | 5 |
5 | Leaf sheaths and blades tomentose, covered by dense short and sparse long hairs; lemma 12–18 mm, awn 11–17mm | B. tomentellus |
– | Leaf blades and sheaths glabrous, scarcely scabrid on the veins or distinct pilose, not tomentose; lemma 8–10(–15) mm, awn 7–9 mm | B. moellendorffianus |
6 | Leaf sheaths lanate-pubescent, with long and tangled hairs; the lower sheaths fibrous; panicle denser; lemma 8–9 mm | B. condensatus |
– | Leaf sheaths not lanate-pubescent, the lower sheaths persistent, remaining intact when dead; panicle lax, lemma > 9 mm | 7 |
7 | Glumes subequal, florets strongly overlapped, for ¾ of their length by the floret below; panicle spread | B. erectus |
– | Glumes markedly unequal; florets only slightly overlapped by the apex of the floret below | 8 |
8 | Lower sheaths densely pubescent; lemma 13–18 mm, longer than the upper glume; awn up to one half of lemma length | B. stenophyllus |
– | Sheaths glabrous or with few scattered long (c. 1 mm) hairs; lemma short, c. 10 mm, similar in length to the upper glume; awn similar to lemma length | B. transsilvanicus |
Asturias: Vegarredonda, 43°14.44'N, 4°59.42'W, 1983, July 28, limestone, 1800 m alt., H.S.Nava s.n. (FCO 14203). Cantabria: Canal de Jenduda, 43°9.88'N, 4°48.88'W, 20 July 2008, 1810 m alt., C.Acedo & F.Llamas (v.v.); Canal de San Carlos, 43°12.70'N, 4°41.56'W, 6 August 1983, 1718 m alt., H.S.Nava s.n. (FCO 14201); Canto La Concha, 43°13.13'N, 4°40.81'W, 6 August 1983, 1660 m alt., H.S.Nava s.n. (FCO 14196); Majada de la Redondal, 43°12.52'N, 4°43.41'W, 3 August 1983, 1800 m alt., H.S.Nava s.n. (FCO 14200); Mancondiu, 43°12.96'N, 4°42.47'W, 6 August 1983, 1900 m alt., H.S.Nava s.n. (FCO 14199); Pozo de Ándara, 43°12.67'N, 4°43.80'W, 3 August 1983, 1730 m alt., H.S.Nava s.n. (FCO 14202); Samelar, 43°12.54'N, 4°41.90'W, 1 August 2007, 1700 m alt., C.Acedo & F.Llamas (v.v.); Vegas de Ándara: Fuente de la Escalera, 43°12.42'N, 4°42.20'W, 31 August 2011, 1869 m alt., C.Acedo, A.Alonso & F.Llamas CA247.1 (LEB121812); ibidem CA247.2 (LEB 121810); ibidem CA247.3 (LEB 121811); ibidem CA247.4, (LEB 121814); ibidem CA247.5 (LEB 121813); 50m East of the Fuente de la Escalera, 43°12.43'N, 4°41.99'W, 1 October 2017, 1886 m alt., V.Ezquerra & C. Frey s.n. (LEB 121815); Camino hacia Fuente de la Escalera, 43°12.46'N, 4°42.01'W, 1 October 2017, 1860, V.Ezquerra & C.Frey (v.v.), sink holes, 43°12.66'N, 4°42.25'W, 1 October 2017, 1789, V.Ezquerra & C.Frey (v.v.), road margin, 43°12.70'N, 4°42.24'W, 1 October 2017, 1787 m alt., V.Ezquerra & C.Frey (v.v.). León. Carbayal, 43°11.82'N, 4°57.11'W, 7 July 1983, 1800 m alt., H.S.Nava s.n.(FCO 14198); Las Colladinas, 43°10.84'N, 4°51.76'W, 22 July 1983, 2170 m alt., H.S.Nava s.n. (FCO 14197).
This research was partially supported by the Spanish Ministerio de Ciencia e Innovación, and Spanish Ministerio de Economía y Competitividad under Flora Iberica X (CGL2014-52787-C3-2-P/BOS), GrassModels (CGL2012-39953-C02-02), and Pooide (CGL2009-12955-C02-02) projects. The authors give many thanks to the curators of all the herbaria consulted, and would like to thank herbaria B, C, JBAG, LEB, FCO, FI, JACA, K, MA, MAF, MSNM, P, SALA, SANT, and VIT, and researchers who provided material from public or personal collections and provided loans and access to collections, although in some cases it was not included in this study. Thanks to Víctor Ezquerra and Carlos Frey for collecting the fruiting specimens in the locus classicus; Ms. Giulia Osti for drawing the holotype; Estrella Alfaro Ph.D. (LEB) for improving the distribution map, and Mrs. Amelia Llamas for proofreading the paper. Many thanks to the reviewers Martin Röser and Jeffery Saarela, and the communicating editor Maria Vorontsova for suggestions to improve the manuscript.